Marine exhaust system



FIG. 1 is a perspective view of one embodiment of a marine exhaust system illustrating my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

Any elements shown in dash-dot lines form no part of the claimed invention, and are instead included to show environmental aspects of the claimed invention. The dashed lines form an unclaimed boundary of the design. 

CLAIM The ornamental design for a marine exhaust system, as shown and described. 